The invention relates to a printing unit of a rotary printing press. A cylinder, roller or spindle has an outside support surface which is located between barrel ends of a barrel of the cylinder. A support device acts on this support surface.
Printing units, wherein the circumference of the form cylinder essentially corresponds to the section length of the associated folding apparatus are known for job printing, for example from DE 44 29 891 A1, as well as for newspaper printing, for example from DE 198 15 294 A1.
In connection with the printing component for job printing, it is proposed to make the diameter of the rubber blanket cylinder at least twice as large as that of the form cylinder. With the printing component for newspaper printing, the forme cylinder and the rubber blanket cylinder have the same circumference, essentially the length of one newspaper page. With both printing components for both press types, the plate cylinders can have the same length, for example 1240 mm, 1600 mm, etc. In principle it is possible with each type of printing component, i.e. also with the job printing unit, to print four newspaper pages next to each other.
U.S. Pat. No. 1,733,707 discloses a printing unit, whose forme cylinder and counter-pressure cylinder have intermediate support rings.
It is the object of the present invention to create a printing unit.
This object is attained by providing at least one forme cylinder of a rotary printing press with an outer support surface between barrel ends of its barrel. An ink roller or ink transfer roller of the printing unit also has a support surface between its ends. Support devices are arranged outside of the barrels and act on the support surfaces.
The advantages which can be achieved by the present invention reside, in particular, in that forme cylinders with a forme cylinder quotient (cylinder barrel length divided by the cylinder barrel diameter) i=3.5 and larger can be used without oscillation strips worth mentioning. It is possible to employ extremely long and slim forme cylinders. These can be equipped for receiving sleeves or printing plates.